Method and device for the individual control of selecting members



Nov. 8, 1966 A. DE CERJAT 3,283,541

METHOD AND DEVICE FOR THE INDIVIDUAL CONTROL OF SELECTING MEMBERS Filed Feb. 15, 1964 5 Sheets-Sheet 1 uvvewrow AVMON oz: CERJAT Z flTTCj/VEV A. DE CERJAT 3,283,541 METHOD AND DEVICE FOR THE INDIVIDUAL CONTROL Nov. 8, 1966 OF SELECTING MEMBERS Filed Feb. 15, 1964 5 Sheets-Sheet 2 INVENTOR AYMON DE CERJAT flTTOR NE VS Nov. 8, 1966 A. DE CERJAT 3,283,541

METHOD AND DEVICE FOR THE INDIVIDUAL CONTROL OF SELECTING MEMBERS Filed Feb. 13, 1964 5 Sheets-Sheet 5 /NVENTC)F? AYMON DE CERJA T BY 7L/ ATTORNEYS United States Patent 3,283,541 METHUD AND DEVICE FOR THE INDIVIDUAL CONTROL OF SELECTING MEMBERS Aymon de Cerjat, Convet, Neuchatel, Switzerland, as-

signor to Edouard Dubied et Cie (Socit Anonyme), Convet, Neuchatel, Switzerland Filed Feb. 13, 1964, Ser. No. 344,754 Claims priority, application Switzerland, Feb. 14, 1963, 1,883/63 11 Claims. (Cl. 66-50) This invention relates to a method for the individual control of the members of a selector device, particularly for the individual selection of needles of a knitting machine, by magnetic deflection and attraction jacks each coacting with one needle, towards the one or the other of the two pole faces of a magnet.

The invention also relates to a device for carrying out this method, said device comprising a magnet having an air gap through which the jacks are adapted to travel in succession and a control electromagnet having a winding connected to a source which supplies electric impulses in accordance with a predetermined program.

The object of an individual selection, for example of needles of a knitting machine, is the successive and continuous separating of the needles into active and inactive needles, in order to knit patterns resulting from different types of stitches, or from the use of threads of different colors in Jacquard patterns, or even from stitch transfer in fashioned knit fabrics. Such selection is generally made by means of jacks guided in grooves which are provided in a part of the machine. The selection consists in an individual control of the jacks to be placed into or out of operation. Dependent on the type of the machine the jacks travel in succession in front of a selector device, or this device is movable with respect to the stationary jacks.

Different types of mechanically or electromechanically operated selector devices are known, the latter being much more suitable for an automatic control of the machines. Among these devices the most advantageous are those which are operating according to the principle of electromagnetic attraction of the jacks against the pole faces of an electromagnet which can be controlled by electric impulses in accordance with a predetermined program.

In known devices operating by magnetic attraction a counter force is generally applied, counteracting the magnetic attraction force, in order to prevent the not selected jacks from leaving their inoperative position. This retaining force is usually obtained by suitable mechanism having one or a plurality of springs, or using the frictional resistance of the jacks in their guiding grooves or even the own weight of the jacks. The mechanism for adjusting the equilibrium between the different forces acting on the jacks has the disadvantage to be very susceptible to wear, dirt, and to mechanical vibrations resulting from normal operation of a knitting machine. These devices have furthermore the disadvantage of allowing only a very short selection path. Thus the locking of the movable members in selected position by the known methods is quite unreliable.

It is an object of the invention to provide a method for the individual operation of selector members which avoids the mentioned disadvantages by actuating the pushers exclusively by magnetic forces, either for placing them into operating position or out of operating position, and by combining the locking action with the selecting action without leaving any discontinuity.

The invention will be fully disclosed in the following specification of which the accompanying drawings form a part and represent by way of example two embodiments of a device for the selection of the needles of a knitting machine.

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FIGURE 1 is a sectional view of a device according to the invention and of a portion of the cylinder of a circular knitting machine comprising needles and jacks.

FIGURE 2 shows the position of a jack when leaving the device of FIGURE 1, after having been selected to be placed out of operation.

FIGURE 3 shows the position of a jack when leaving the device of FIGURE 1 after having been selected to be placed in operation.

FIGURE 4 is a vertical section on the line IV-IV of FIGURE 1.

FIGURE 5 is a section on the line V-V of FIGURE 4.

FIGURE 6 is a vertical section similar to that of FIG- URE 1, showing a modification of the invention.

FIGURE 7 is a section on the line VIIVII of FIG- URE 6.

As shown in FIGURE 1 the selector device comprises a magnet, an electromagnet and a support 7, made of nonmagnetic material. The support 7 forms a portion of the frame of the knitting machine. The magnet is provided with two pole pieces 1 and 2 having pole faces 15 and 16 adapted to contact the jacks, a core 3 and two identical windings 4 adopted to be connected to a directcurrent source, to provide a steady magnetic field. The control electromagnet comprises a core 5 fixed to the center of the core 3 and a winding 6 adapted to be connected to a source of electric impulses polarized in accordance with a predetermined program. Individual pulses pass through the winding 6 in the one or the other direction, thereby polarizing the magnet in the one or other direction; that is, if given ends of the electromagnet are north and south poles, respectively, for one direction of polarization, polarizing the magnet in the opposite direction reverses the polarity of the magnet.

The represented portion of the cylinder 8 of a circular knitting machine comprises conventional vertical grooves 9 in which are guided jacks 10 and needles 11 movable in axial direction. Each jack is provided with a head 12 forming a fulcrum to permit a pivoting movement of the jack in its groove, and with a projecting butt 13 cooperating with a member of the knitting machine, e.g. a lifting cam 14, adapted to impart an axial displacement to the jack when the latter has been selected to be put in operation.

FIGURE 3 shows the position of jack when it leaves the selector device, after having been selected to be put in operation, ie a position in which the lug 13 can cooperate with the cam 14, so as to produce a lifting movement of the jack and its corresponding needle 11.

FIGURE 2 shows the position of a jack after it has been selected to be put out of operation, i.e. into a position in which the lug 13 can not be actuated by the cam 14.

FIGURE 4 shows the position of the jacks 10 moving in the direction of arrow 17 within the air gap of the magnet formed between the pole pieces 1 and 2; the lower end of the jacks passes in proximity of the core 5 of the control electromagnet.

FIGURE 5 shows the guide slot for the passage of the jacks 10, said slot being formed between the pole faces 15 and 16 of the pole pieces 1 and 2 of the magnet. The opposite faces of the slot first converge to a point of constriction and then diverge again. At the constricted point 13, the jacks are in close proximity of the two pole faces as well as of the end of the core 5 of the electromagnet. This latter is adapted to deflect the jacks against one or the other of the two pole faces 15 and 16, depending on the predetermined program.

The described selector device operates as follows:

The cylinder 8 of the knitting machine is rotating in the direction of the arrow 17 (FIG. 5), whereby all the jacks 10 carried by the cylinder are successively engaged between the pole pieces 1 and 2 of the magnet. They are maintained in contact with the faces 15 or 16 by the magnetic forces exerted on them during the whole period of their passage between the two faces. At the point of constriction 18 each jack passes into the zone of action of the control electromagnet. The magnetic field of this electromagnet locally produces a state of disequilibrium of the magnetic forces of attraction acting on the jacks, in the pole face gap at the point of constriction, thereby deflecting each jack towards one or the other of the pole faces of the magnet, corresponding to the polarization which it receives in accordance with the predetermined program. The diverging pole faces, after the point of constriction of the gap, form a widening of the passage way for the jacks and therefore amplify the course of deflection of the jacks obtained owing to the magnetic attraction forces applying the jacks against one or the other of the opposite inclined faces 15 and 16. When a jack (see FIG. 5) arriving in front of the core 5 of the control electromagnet, must be selected for operation, an electric impulse is supplied to the winding 6 so that the direction of polarization of the resulting magnetic field is such that it amplifies locally the magnetic field of the magnet on the pole face 15 and reduces this field on the pole face 16. Thus, the jack is attracted by the pole face 15. As soon as the jack has left the zone of action of the control electromagnet, it is maintained by magnetic attraction on the pole face 15 during the time of its passage along the slot, as shown for jacks 10b, 10d and 10 until it is engaged in known manner by the lifting cam 14 of the knitting machine.

In the case when the jack 10:: must be selected to be put out of operative position, an electric impulse of opposite polarity is fed to the winding 6, so that the disequilibrium of the magnetic forces, contrary to the preceding case, is such that the jack is attracted into the pole face 16. When it has left the zone of action of the control electromagnet, it is also maintained against the pole face 16 by magnetic attraction during the time of its passage as shown for jacks 16c, 1%, so that it can not be actuated by the lifting cam 14.

It is seen that the jacks are exclusively actuated by magnetic forces; accordingly, no wear of additional mechanical members, such as springs or brake members, is possible, as would result from friction of the jacks in their grooves. Furthermore, the point of constriction 18 of the pole faces in the zone of action of the control electromagnet may be such that there is only a small clearance between the two faces i5, 16 and a jack passing therethrough; this reduces the amount of deflection and the time required for effecting this deflection to very small values. A selector device according to the present invention can operate at very high speeds, and may be applied to knitting machines of any type as well as to other machines where a quick selection of similar operating members is required.

It will be understood that the magnet 1, 2 may be constituted of one or a plurality of permanent magnets, made egg. of ferrite, for providing a steady magnetic field.

In a modification, the method and selector device according to the invention allow constructions which are symmetrical with respect to an axis perpendicular to the axis of movement of the jacks and passing through the center of the core of the electromagnet. It results therefrom that such a device can effect an individual selection of jacks moving through the slot between the pole face in one or the other direction of movement.

This particular feature of the invention makes it possible to use the selector device with flat knitting machines of the reciprocatory type.

Also, the invention is not limited to a selector device applied to the cylinder of a circular knitting machine, but the device may also be applied to a plate thereof.

In a modification, the control electromagnet comprises two different windings adapted to be connected to a source delivering impulses alternatively to one or the other wind- 4 ing depending on a predetermined program, so as to polarize the electromagnet in two different directions.

In a further modification the control electromagnet may be arranged outside of the other magnet in order to cooperate with one of the lateral faces of the jacks (see FIGURES 6 and 7). As shown, the device comprises a magnet, an electromagnet and an alignment cam. The permanent magnet 21 is provided with pole members 1 and '2 in the air gap of which pass the jacks 10 between the pole faces 15 and 16. The electromagnet arranged, outside of the magnet comprises a horseshoe-shaped core 25 with inclined pole faces for the deflection of the jacks and a winding 6 connected to a source adapted to deliver impulses in accordance with a predetermined program.

The cam 19 is arranged to deflect the jacks and to align them all against the pole face 16.

The device represented in FIGURES 6 and 7 operates as follows:

When the cylinder 8 of the knitting machine rotates in the direction of arrow 17, all jacks 10 carried by the cylinder are deflected by means of cam 19 against the pole face 16 of the magnet, where they are maintained by magnetic attraction. The jacks aligned in this manner pass in close proximity of the front edge of the core 25 of the control electromagnet.

When the jack 10a arriving in front of the control electromagnet, must be selected for operation, an elec' tric impulse is supplied to the electromagnet. The resultant of the magnetic attraction forces acting on this jack produces a condition of disequilibrium, so that the jack is deflected against the inclined pole faces of the core 5 of the control electromagnet. The jack then is maintained against the inclined pole faces and deflected towards the pole face 15 of the magnet 20, against which it is maintained by the magnetic forces, as in the case of jacks Nb and Tile in FIGURE 7. This pole face 15 may be inclined so as to increase the length of selection until the butts 13 of the jacks engage the lifting cam 14.

On the other hand when the jack 10a, passing in front of the control electromagnet, must not be selected no impulse is supplied to its winding and the jack remains in contact with the pole face 16 by magnetic forces, as shown for jacks Mic, 10d and 10 This pole face may also 'be inclined to further move the butt 13 away from the lifting cam 14.

I claim:

l. A device for the individual operation of the needles of a knitting machine by controlling the jacks: a magnet providing a steady magnetic field, said magnet having a pair of pole faces separated by an air gap in which the two opposite pole faces of said magnet form a constricted passage of the path of travel of said jacks along said portion of the air gap; an electromagnet that can be polarized by electric pulses in accordance with a predetermined program, said electromagnet being located adjacent a portion of said jack and with respect to said air gap that polarization of the electromagnet causes a disequilibrium of the magnetic forces acting on a jack while it passes along a portion of the air gap, whereby a jack passing through said portion of the air gap when the electromagnet is polarized is attracted to a pole face of said magnet and is held to the face by magnetic attraction.

7;. A device as claimed in claim 1, in which said constricted passage opens, in the direction of movement of the jacks through the air gap, into a diverging passage formed by the opposed pole faces, for amplifying the selection movement of the jacks.

3. A device as claimed in claim 1, in which the electromagnet is disposed within the pole pieces of said first mentioned magnet, one of the poles of the electromagnet being situated in proximity to the pole faces of said magnet, and the other pole of the electromagnet being situated in the core of said magnet.

4. A device as claimed in claim 1, in which the electric pulses supplied to the electromagnet are of different polarity according to a predetermined program, whereby the electromagnet is polarized in one or the other direction depending on the polarity of the pulse, and whereby the jack passing through said portion of the air gap is attracted to the one or other pole face in dependence on the direction of polarization of the electromagnet.

5. A device as claimed in claim 1, in which the electromagnet is provided with two separate windings adapted to be connected to a source of electric impulses supplied alternatively to one or the other of the two windings according to a predetermined program, so as to polarize the electromagnet alternatively in two opposite directions, whereby the jack passing through said portion of the air gap is attracted to the one or the other pole face in dependence on the direction of polarization of the electromagnet.

6. A device :as claimed in claim 1, in which the parts of the device are symmetrically arranged to be operative in combination with jacks travelling in one or the other of two opposed directions of movement, so that the device can be applied to fiat knitting machines of the reciprocating type.

7. A device according to claim 1, said jacks having each a lateral face; means for causing all of said jacks to bear against the same one of said pole faces as they enter said air gap; said electromagnet being located adjacent said lateral face to attract a jack, when said electromagnet is fed a pulse, to cause that jack to be brought from said one pole face to the other pole face of said magnet, where the jack is held by magnetic attraction.

8. A device according to claim 7, wherein those jacks are moved to the other pole face which are to operate the needles.

9. A device according to claim 1, wherein said disequilibrium occurs within said air gap along said portion thereof.

10. A device according to claim 1, wherein the movement of a jack to a pole face is pivotal.

11. A device according to claim 10, including the cylinder of a circular knitting machine; each jack having a head portion; grooves in said cylinder, for guiding said jacks and supporting said jacks by their heads for pivoting.

References Cited by the Examiner FOREIGN PATENTS 883,432 11/1961 Great Britain.

MERVIN STEIN, Primary Examiner.

DONALD W. PARKER, Examiner.

R. F. FELDBAUM, Assistant Examiner. 

1. A DEVICE FOR THE INDIVIDUAL OPERATION OF THE NEEDLES OF A KNITTING MACHINE BY CONTROLLING THE JACKS: A MAGNET PROVIDING A STEADY MAGNETIC FIELD, SAID MAGNET HAVING A PAIR OF POLE FACES SEPARATED BY AN AIR GAP IN WHICH THE TWO OPPOSITE POLE FACES OF SAID MAGNET FORM A CONSTRICTED PASSAGE OF THE PATH OF TRAVEL OF SAID JACKS ALONG SAID PORTION OF THE AIR GAP; AN ELECTROMAGNET THAT CAN BE POLARIZED BY ELECTRIC PULSES IN ACCORDANCE WITH A PREDETERMINED PROGRAM, SAID ELECTROMAGNET BEING LOCATED ADJACENT A PORTION OF SAID JACK AND WITH RESPECT TO SAID AIR GAP THAT POLARIZATION OF THE ELECTROMAGNET CAUSES A DISEQUILIBRIUM OF THE MAGNETIC FORCES ACTING ON A JACK WHILE IT PASSES ALONG A PORTION OF THE AIR GAP, WHEREBY A JACK PASSING THROUGH SAID PORTION OF THE AIR GAP WHEN THE ELECTROMAGNET IS POLARIZED IS ATTRACTED TO A POLE FACE OF SAID MAGNET AND IS HELD TO THE FACE BY MAGNETIC ATTRACTION. 